Negotiations for Russia to supply Iran with the advanced S-300 surface-to-air missile system hit a snag over Russia’s demand that Iran end its lawsuit for failure to deliver the system under a previous contract.The talks over a new contract are ongoing, but the two countries are still unable to agree on how to proceed regarding Iran’s lawsuit, a source in the Russian military-technical cooperation establishment told the state-run TASS news agency in a report published on Wednesday evening. “Consultations are in progress.A final agreement has not been reached yet. Iran says it will revoke the lawsuit regarding the previous contract when it gets the first batch of products under the new one, while Russia insists the lawsuit should be revoked before it takes any action under the newly concluded deal,” the source said.The source added that Russia was firm in its decision to supply Iran with the air defense system, saying that a compromise could be reached where delivery and cancellation of the lawsuit could occur simultaneously.Vyacheslav Davidenko, spokesman for Russia’s state-owned arms export monopoly Rosoboronexport, declined to comment.Russia and its state media have made numerous statements regarding the sale or delay of the delivery of the S-300 system over the years. The often contradicting reports appear to be a propaganda operation that changes according to the country’s political interests.“It is a game two can play.From time to time Iranians are those who make declarations on the S-300. I guess to pressure the Russians and the US,” Yuri Teper, an expert on Russia from Ariel University, told The Jerusalem Post on Thursday.“Russians are known for making a lot of fuss about very little or unfinished deals, as happened with their energy deal with the Chinese,” Teper said a day earlier.Iran would sign a contract with Russia this week to buy four S-300 surface-to-air missile systems, the Iranian defense minister said last week.Russian state arms producer Almaz-Antey in June said it would supply Iran with a modernized version of the S-300, among the world’s most capable air defense systems, once a commercial agreement was reached.In 2010, under Western pressure, Russia suspended a 2007 agreement to sell five S-300 batteries to Iran under a contract then reported to be worth some $800 million.Reuters contributed to this report.